Dyeing hair with 2, 3, 6-triaminopyridine and salts thereof



United States Patent 3,359,168 DYEING HAIR WITH 2,3,6-TRIAMINOPYRIDINEAND SALTS THEREOF Stanley Brechner, West Orange, and Leonard A. Como,Franklin Boro, N.J., assignors to Warner-Lambert Pharmaceutical Company,Morris Plains, N.J., a corporation of Delaware No Drawing. Filed Aug. 3,1966, Ser. No. 569,851 8 Claims. (Cl. 167-88) The present inventionrelates to a method employing novel compositions comprising2,3,6-triaminopyridine or its salts for dyeing hair to impart agreenish-blue color thereto as well as to compositions combining said2,3,6- triaminopyridine together with other dyes to give other shades.

It is known in the art that in order to produce bluish or greenish-blueshades when dyeing hair with amine dyes, one must employ at least twoseparate oxidizable amines. For example, aminobenzenes such asm-diaminobenzenes or derivatives thereof must be combined with otheramines such as oor p-diaminobenzenes and on oxidation with asuitable'oxidizing agent such ashydrogen peroxide, urea peroxide, sodiumborate and the like, the combination yields a blue color;2,6-diaminop'y'ridines or substituted 2, 6-diaminopyridines must becombined with aminobenzenes to give a blue color on oxidation. Forexample, US. Patent No. 3,200,040 discloses that 2,6-diaminopyridine orsubstituted 2,6-diaminopyr'idine's in combination with certaindiaminobenzenes or aminophenols will produce a blue color on treatmentwith oxidizing agents. The 2,6- diaminopyridine alone produces only apale yellow color. Accordingly, combination products were the onlyproducts available heretofore if it were desired to impart a blue shadeto the hair employing oxidizable amines. We have now found that agreenish-blue color may be imparted to hair-by oxidation employing but asingle oxidizable amine. Accordingly, we provide novel compositions ofmatter containing but a single oxidizable amine which when treated withan oxidizing agent yields a greenishblue dye which may be used to dyehair with a remarkable degree of consistency where the intensity ofcoloration imparted to hair is not only controllable but reproducibletime after time.

In accordance with this invention, these novel and highly desirableresults are attained by treating hair with a comp sition containing2,3,6-triaminopyridine in amounts described below and in the presence ofa suitable oxidizing agent. The intensity of coloration produced on hairis in direct proportion to and dependent upon the concentration of2,3,6-triaminopyridine employed. Generally speaking, a satisfactorygreenish-blue color may be obtained by applying to the hair acomposition containing about 0.01% to 2.0% by weight of2,3,6-triaminopyridine and then oxidizing the dye in said composition insitu.

The 2,3,6-triaminopyridine used in this composition is prepared bycatalytically reducing 3-phenylazo-2,6-diaminopyridine in the presenceof hydrochloric acid as described below in Example 1.

The 2,3,6-triaminopyridine may be employed in the form of its acidaddition salts, such as 2,3,6-triaminopyridine dihydrochloride,2,3,6-triaminopyridine sulfate and other suitable salts.

Such salts are readily prepared by the usual methods, such as, forexample, the reaction of a stoichiometrically equivalent amount of thebase and the desired acid in an inert common solvent. Examples of acidswhich are suitable for the preparation of acid addition salts of theamine base of this invention are inorganic acids, such as, for example,hydrochloric, nitric, sulfuric, phosphoric, and the like acids, andorganic acids, such as, as for example, benzoic, acetic, salicyclic,maleic, tartaric, citric and the like acids.

The 2,3,6-triaminopyridine in the form of its free base or in the formof its acid addition salts may then be dissolved in water and used assuch or they may also be dissolved in a suitable vehicle for carryinghair dyes such as those described by Kass in American Perfumer andAromatics, vol. 68, No. 1, pp. 25-28, July 1956. Examples of suchvehicles are those that contain ammonium oleate, fatty acid esters,fatty alcohols, ethoxylated fatty alcohols, fatty amines, ethoxylatedfatty amines, phosphate esters and the like. These vehicles mayoptionally contain wetting agents such as the condensation product offatty acids containing 6 to 20 carbon atoms with diethanolamine ormonoethanolamine, the condensation product of the methyl esters of fattyacids with diethanolamine or monoethanolamine. The term fatty acids usedin the above description includes acids such as capric, lauric,myristic, palmitic, stearic, linoleic, oleic, ricinoleic, linolenic ormixtures of fatty acids occurring in natural fats and oils such astallow, cocoanut oil, castor oil and the like.

The term fatty alcohols used in the above description includes alcoholsuch as lauryl alcohol, oleyl alcohol, myristy-l alcohol, cetyl alcohol,stearyl alcohol, alcohols extracted from lanolin and the like,and'mixtures thereof.

The active ingredient may be present in amounts of from about 0.01 to2.0% by weight. The final solution may have a pH value of about 8 to 11and this may be achieved by the addition of a base such as ammoniumhydroxide. I

For use the user combines the solution containing the active ingredientwith about 1 to 2 parts by volume or by weight of a suitable oxidizingagent such as urea peroxide, hydrogen peroxide, sodium borate and thelike. The choice of the oxidizing agent is not critical and otherconventional oxidizing agents useful in hair bleaching may also be used.The amine oxidizing agent mixture is then applied to hair desired to bedyed. The solution is allowed to remain in contact with the hair forabout 10 to 30 minutes. The hair is then shampooed and after drying isfound to assume the new shade.

We have found that 2,3,6-triaminopyridine if desired may also becombined with other amines such as those disclosed in US. Patent No.3,200,040 or diaminobenzenes or combinations thereof to give other haircoloring compositions.

For example, 0.01% to 2.0% by weight of 2,3,6-triaminopyridine may becombined with 0.01% to 2% by weight of o-, mor p-diaminobenzenes orcombinations of o-, mor p-diaminobenzenes to give other colorations.Instead of using diaminobenzenes in these combinations we have found o-,mor p-diaminopyridines may be used.

The following examples are included. in order to further illustrate theinvention.

Example 1.Preparation of 2,3,6-triaminopyridine A suspension of 124.5 g.(0.5 mole) of 3-phenylazo- 2,6-diaminopyridine in 500 m1. of water and200 ml. of 37% HCl is reduced in a Parr hydrogenator in the presence of0.4 g. of 5% Pd on carbon catalyst. The reduction proceeds rapidly tocompletion at 20 to 30 C. The catalyst is filtered at once before theproduct can precipi tate and the colorless filtrate is diluted with anequal volume of isopropanol. After standing in the cold for severalhours the dihydrochloride precipitates as transparent colorless prismsand is filtered, washed with isopropanol and dried to constant weight invacuo. The first crop weighs 41 g. and melts with decomposition startingabout 230 C. A second crop can be obtained by concentration of thefiltrate to give a total yield of about 70% of theory.

3 If necessary, the material can be further purified by dissolving in asmall quantity of water and precipitating with excess HCl.

The compositions of the following Examples 2 to 7 are prepared by simplemixing procedures.

Example 2 Greenish-blue coloration:

2,3, 6-triaminopyridine dihydrochloride percent by weight 0.02 Thecondensation product of 10 moles of ethylene oxide and nonyl phenol do20.0 Sodium sulfite (as antioxidant) do 0.25 Sufficient ammonia solutionto yield a solution having a pH 9. Distilled water to make percent byvolume 100.00

Example 3 Light warm brown coloration:

Ammonium oleate percent by weight 20.00 p-phenylenediamine do 0.252,3,6-triaminopyridine dihydrochloride do 0.15 Anti-oxidant (sodiumsulfite) do 1.00 Ammonia (2 8%) to adjust the pH to 9.5. Distilled waterto make percent by volume 100.00

Example 4 Dark ash brown coloration:

Laurie diethanolamine percent by weight 3.00 Ammonium oleate do 2.50p-phenylenediamine do 0.25 2,3,6-triamin0pyridine dihydrochloride do0.25 Anti-oxidant (sodium sulfite) do 1.00 Ammonia (28%) to pH 9.5.Distilled water to make percent by volume 100.00

Example 5 Dark blue-black coloration:

Cocoanut monoethanolamide percent by weight 2.00 Propylene glycol do6.00 p-phenylenediamine do 0.85 2,3,6-triaminopyridine dihydrochloridedo 1.10 Anti-oxidant do 1.00 Ammonia (28%) to pH 9.5. Distilled water tomake percent by volume 100.00

Example 6 Orange red coloration:

Triethanolamine lauryl sulfate percent by weight 20.002,5-diaminopyridine dihydrochloride do 0.50 2,3,6-triaminopyridinedihydro chloride do 0.05 Anti-oxidant do 0.25 Ammonia (28%) to pH 9.0.Distilled water to make percent by volume 100.00

Example 7 Lightwarm brown coloration:

Ammonium oleate percent by Weight 20.00 2,5-diaminopyridinedihydrochloride do 0.45

4 2,3,6-triaminopyridine dihydrochloride do 0.025 Anti-oxidant do 0.25Ammonia (28%) to pH 9.0. Distilled water to make percent by volume100.00

Example 7.4

Diester of phosphoric acid and oleic acid percent by weight 5.00Monoester of phosphoric acid and oleic acid do 5.00 2,5-diaminopyridinedihydrochloride do 0.40 2,3,6-triaminopyridine dihydrochloridemonohydrate do 0.06 Anti-oxidant do 0.25 Ammonia (28%) to pH 9.0.Distilled water to make percent by volume 100.00

Example 8 Medium ash brown coloration:

The condensation product of 10 moles of ethylene oxide and nonyl phenolpercent by weight" 20.00 2,54iiaminopyridine dihydrochloride -do 0.402,3,6-triaminopyridine dihydrochloride do- 0.05 Anti-oxidant -do 0.25Ammonia (28%) to pH 9.0. Distilled water to make percent by volume100.00

Example 9 In order to use these compositions to impart the de siredshade to human hair one part of the selected composition is mixed withapproximately 1 to 2 parts of 6% hydrogen peroxide solution.

The resulting solution is then applied to white hair and allowed toremain in contact with the treated hair for about half an hour afterwhich the hair is rinsed and shampooed. After drying the hair assumesthe shade as described.

It is understood that the foregoing detailed description is given merelyby way of illustration and that many variations may be made thereinwithout departing from the spirit of our invention.

We claim:

1. Process for imparting a greenish-blue coloration to hair whichcomprises contacting hair with an aqueous solution of about 0.01% to 2%by weight of 2,3,6-triaminopyridine or the salts of2,3,6-triaminopyridine in the presence of an oxidizing agent.

2. Process for imparting a greenish-blue coloration to hair whichcomprises. contacting said hair with an aqueous solution containingabout 0.01% to 2% by weight of 2,3,6-triaminopyridine or the salts of2,3,-6-triaminopyridine in the presence of a hydrogen peroxide solution.

3. A composition for dyeing hair which comprises as active ingredient ofabout 0.01% to 2% by weight of 2,3,6-triaminopyridine or the salts of2,3,6-triaminopyridine in an aqueous solvent.

4. A composition for dyeing hair which comprises as active ingredient ofabout 0.01% to 2% by weight of 2,3,6-triaminopyridine or the salts of2,3,6-triaminopyridine and about 0.01% to 2% by weight of2,6-diaminopyridine.

5. A composition for dyeing hair which comprises as active ingredientsabout 0.01 to 2.0% by weight of 2,3,6- triaminopyridine and 0.01% to2.0% of o-, m-, or p-diaminobenzenes or combinations thereof.

6. A method for dyeing hair which comprises contacting hair with acomposition in accordance with claim 5 in the presence of an oxidizingagent.

6 7. A method in accordance with claim 6 wherein said References Citedggigilizriilieifiglliiteis hydrogen peroxide, urea peroxide or UNITEDSTATES PATENTS 8. A composition for dyeing hair which comprises as3,200,040 8/1965 Lange at 167 88 active ingredients of about 0.01 to2.0% by weight of 5 2,3,6-triaminopyridine and 0.01% to 2.0% of 0-, m-,or ALBERT MEYERS Prlmary Exammer' p-diaminopyridines. VERA C. CLARKE,Assistant Examiner.

1. PROCESS FOR IMPATING A GREENISH-BLUE COLORATION TO HARI WHICHCOMPRISES CONTACTING HAIR WITH AN AQUEOUS SOLUTION OF ABOUT 0.01% TO 2%BY WEIGHT OF 2,3,6-TRIAMINOPYRIDINE OR THE SALTS OF2,6,6-TRIAMINOPYRIDINE IN THE PRESENCE OF AN OXIDIZING AGENT.